1. Technical Field
The present invention relates to a liquid ejection apparatus.
2. Related Art
As a typical liquid ejection apparatus ejecting liquid onto a target, an inkjet printer (hereinafter, referred to as a “printer”) is generally known. The printer includes a recording head (a liquid ejection head) and an ink cartridge that supplies ink (liquid) to the recording head. The ink is then ejected from nozzles defined in the recording head onto a recording medium, which is a target, to subject the recording medium to printing.
In this printer, the nozzles of the recording head may be clogged through evaporation of solvent of the ink from the nozzles, which increases the viscosity of the ink and thus solidifies the ink. Clogging of the nozzles may be caused also by deposition of dust or generation of bubbles. These factors causing nozzle clogging lead to a printing problem. To solve this problem, the printer normally performs flushing, or forcible drainage of the ink from the nozzles independently from ejection of the ink onto the target.
Also, to enable high-speed printing, a large-sized full-line type printer has been proposed. This type of printer includes nozzles that are aligned along the entire width of a printing area and in a direction perpendicular to the transport direction of the recording medium. The weight of the recording head of the printer is thus increased, making it difficult to move the recording head out of the printing area for carrying out flushing. Accordingly, it is required that the flushing be accomplished without moving the recording head out of the printing area.
To meet the requirement, JP-A-2000-211159, for example, describes a printer having an auxiliary ejection cover (a liquid receiving member), which is arranged between a recording head and a recording medium. An opening sized in correspondence with the size of a nozzle surface is defined in the auxiliary ejection cover. The auxiliary ejection cover is reciprocated between a position at which the opening opposes the nozzle surface of the recording head and a position other than the position opposed to the nozzle surface. Specifically, to perform printing, ink is ejected from the recording head onto the recording medium through the opening of the auxiliary ejection cover. In flushing, the ink is ejected onto the opposing surface of the auxiliary ejection cover.
Normally, to enhance accuracy of printing, it is desirable to decrease the distance between the recording head and the recording medium. However, if the nozzle surface of the recording head is brought excessively close to the recording medium for the above purpose, the auxiliary ejection cover slides on the nozzle surface while being moved for flushing, causing a printing problem. Also, resistance may be caused against movement of the auxiliary ejection cover. Alternatively, if the distance between the recording head and the recording medium is increased (to 3 mm or greater, for example) to avoid generation of such sliding resistance, the ink ejected from the recording head through the opening of the auxiliary ejection cover may run on the recording medium, which also is a printing problem. Further, if some of the ink cannot be received by the recording medium, mist of the ink may generate.